brakes MERCEDES-BENZ A-CLASS HATCHBACK 2021 Owners Manual

1
! ABS →
488
2 #! Turn signal lights →
136
3 h Tyre pressure monitoring system →
490
4 # Electrical fault →
481
5 L Distance warning →
487
6 J Brakes (yellow) →
485
7 J Brakes (red) →
485
8 ! Electric parking brake (yellow) →
485
9 ! Electric parking brake (red) →
485
A % Diesel engine: preglow
B ; Engine diagnostics →
481
C R Rear fog light →
135 D
K High beam →
136
L Low beam →
134
T Standing lights →
134
E å ESP®
OFF →
488
÷ ESP®
→
488
F 6 Restraint system →
477
G Fuel le vel →
278
H æ Reser vefuel wi thfuel /ller 0ap location
indicator →
481
I Ù Powe r steering →
480
J ü Seat belt →
477
K ï Trailer hitch →
480 At
a glance – Indicator and warning lamps (standard)
13
13

1
#! Turn signal lights →
136
2 ï Trailer hitch →
480
3 6 Restraint system →
477
4 å ESP®
OFF →
488
÷ ESP®
→
488
5 R Rear fog light →
135
6 K High beam →
136
L Low beam →
134
T Standing lights →
134
7 ÿ Coolant temp erature →
481
8 Coolant temp erature display →
278
9 ! Electric parking brake (yellow) →
485
A J Brakes (yellow) →
485
B # Electrical fault →
481 C
L Distance warning →
487
D ! ABS →
488
E Ù Powe r steering →
480
F h Tyre pressure monitoring system →
490
G % Diesel engine: preglow
H æ Reser vefuel wi thfuel /ller 0ap location
indicator →
481
I Fuel le vel →
278
J ! Electric parking brake (red) →
485
K ü Seat belt →
477
L J Brakes (red) →
485
M ; Engine diagnostics →
481
N ä Indicator lamp inoperative At
a glance – Indicator and warning lamps (widescreen cockpit)
15
15

Go
vernmental entities are themsel ves, in individ-
ual cases and within the applicable legal frame-
wo rk, authorised toread out data from theve hi-
cle. In the case of an accident, information that
can help with an in vesti gation can, therefore, be
ta ke n from the airbag control unit, forex ample.
Oper
Oper ational dat
ational dat a in t
a in the v
he vehicle
ehicle
This is data rega rding the operation of theve hicle,
which ha vebeen processed bycont rol units.
This includes thefo llowing data, forex ample:
R vehicle status information such as the speed,
longitudinal acceleration, lateral acceleration,
number of wheel revo lutions or thefa stened
seat belts display
R ambient conditions, su chastemp erature, rain
sensor or distance sensor
Generall y,the use of these data is temp orar y;
th ey will not be stored be yond the period of oper-
ation and will only be processed within theve hicle
itself. Control units oTen contain data memories
fo rve hicle keys,fo rex ample. Their use permits
th ete mp orary or permanent documentation of
te ch nical information about theve hicle's operat- ing state, component loads, main
tenance requ ire-
ments and tech nical events or faults.
Depending on theve hicle equipment, thefo llo w-
ing data are stored:
R operating status of system components, such
as /ll le vels, tyre pressure or battery status
R malfunctions or faults in impor tant system
components, such as lights or brakes
R system reactions in special driving situations,
such as airbag depl oyment or the inter vention
of stability cont rol systems
R information on events leading tovehicle dam-
age
In cer tain cases, it may be requ ired tostore da ta
th at wo uld ha veotherwise been used only temp o-
rari ly. This may be the case if theve hicle has
de tected a malfunction, forex ample.
If yo u use services, such as repair services and
maintenance work, stored operational data as
we ll as theve hicle identi/cation number can be
re ad out and used. They can be read out by
service network emplo yees, such as workshops
and manu facturers or third parties, such as break- down services. The same is true in
the case of
wa rranty claims and quality assurance measures.
In general, there adout is per form ed via the legally
prescribed port forth e diagnostics connection in
th eve hicle. The operational data that are read out
document tech nical states of theve hicle or of
individual components and assist in the diagnosis
of malfunctions, compliance with warranty obli ga-
tions and quality impr ovement. Tothat end, these
data, in particular information about component
loads, tech nical events, malfunctions and other
fa ults may be transmitted along with theve hicle
identi/cation number tothe manufacturer. Fur-
th ermore, the manufacturer is subject toproduct
liability. Forth is reason the manufacturer also
uses operational data from theve hicle, forex am-
ple, forre calls. These data can also be used to
ex amine the customer's warranty and guarantee
claims.
Fa ult memories in theve hicle can be reset by a
service outl etor at your requ est as part of repair
or maintenance work. General no
tes
43 43

Therefore, obser
vethefo llowing no tes:
R due tosalt build-up on the brake disks and
brakepads, the braking distance can increase
considerably or result in braking only on one
side
R maintain a much greater safe dis tance tothe
ve hicle in front
To remo vesalt build-up:
R brake occasionally while paying attention to
th e tra1c conditions
R carefully depress the brake pedal at the end of
th e journey and when starting the next jour-
ney
N No ot tes on aq
es on aq uaplaning
uaplaning
Aq uaplaning can take place once a cer tain
amount of water has accumulate d onthero ad
sur face.
Obser vethefo llowing no tes during heavy precipi-
ta tion or in conditions in whi chaquaplaning may
occur:
R reduce speed
R avoid tyre ruts R
avoid sudden steering mo vements
R brake careful ly
% Also obser vethe no tes on regula rly ch ecking
wheels and tyres (/ page 368).
N
No ot
tes on dr
es on dr iving t
iving thr
hrough w
ough w at
ater on t
er on t he r
he road sur-
oad sur-
f
f ace
ace
Wa ter which has entered into theve hicle can
damage the engine, electrics and transmission.
Wa ter can also enter the air intake of the engine
and cause engine damage.
Obser vethefo llowing if you must drive thro ugh
wa ter:
R The water,when calm, may only reach the
lo we r edge of theve hicle body.
R Drive at a maximum speed of 10 km/h; water
can otherwise enter theve hicle interior or
engine compartment.
R Vehicles tr avelling in front, or oncoming vehi-
cles, can create waves which may exceed the
maximum permissible dep thofthewa ter.
The braking e.ect of the brakes is reduced aTer
fo rd ing. Brake carefully while paying attention toth
e tra1c conditions until braking po wer has been
fully restored. EC EC
O st
O st ar
art/st
t/st op function
op function EC
EC
O st
O st ar
art/st
t/st op function
op function
% The ECO start/stop function is not available
in all drive prog rams, depending on the
engine. Obser vethe status display in the
inst rument display forth is.
If all vehicle- related conditions for an automatic
engine stop are met, the engine is switched o.
automaticall y:
R V
V ehicles wit
ehicles wit h manual tr
h manual tr ansmission:
ansmission: You brake
th eve hicle, shiT into neutral iwhen tr avel-
ling at a low speed and then release the clutch
pedal.
R V
Vehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: Yo u
brake theve hicle toa standstill in transmis-
sion position hori.
R You activate the HOLD function or engage
transmission position j.172
172
Driving and parking

-
The vehicle is stationary for a lengt hy
period.
When the electric parking brake is applied, the
re d! indicator lamp lights up in the inst ru-
ment clus ter.
% The electric parking brake is not automatically
applied if theve hicle is switched o. bythe
ECO start/s top function.
F
F unction of t
unction of t he electr
he electric par
ic parking br
king br ak
ake (r
e (r eleasing
eleasing
aut
aut omaticall
omaticall y)
y)
The electr
The electr ic par
ic parking br
king br ak
ake is r
e is r eleased when t
eleased when t he
he
f
f ollo
ollo wing conditions ar
wing conditions ar e
eful/lled:
ful/lled:
R The driver's door is closed.
R The vehicle has been star ted.
R V
V ehicles wit
ehicles wit h manual tr
h manual tr ansmission:
ansmission: age ar has
been selected, youre lease the clutch pedal
and depress the accelerator pedal.
R You apply the brakes and shiT from neutral i
into reve rsege ar k or a forw ard gear ( 1 -
6) when on le velgr ound.
R V
Vehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: the
transmission is in position hork and you depress
the accelerator pedal or you shiT
from transmission position jtoh ork
when on le velgr ound.
R Ifth e transmission is in position k,theta il-
ga te must be closed.
R The seat belt tongue is inse rted into the seat
belt buckle of the driver's seat.
If th e seat belt tongue is not inse rted into the
seat belt buckle of the driver's seat, one of the
fo llowing conditions must be ful/lled:
- You shiT from transmission position j.
or
- You ha veprev iously driven at speeds
gr eater than 3 km/h.
When the electric parking brake is released, the
re d! indicator lamp in the inst rument cluster
goes out. Appl
Appl ying/r
ying/r eleasing t
eleasing t he electr
he electric par
ic parking br
king br ake
ake
manually
manually
Appl Appl ying
ying #
Push handle 1.
The red! indicator lamp lights up in the
inst rument cluster. Driving and parking
217
217

F
F
unction of B
unction of B AS
AS &
W
WARNING
ARNING Risk of an accident caused by a
malfunction in BAS(Brake Assist System)
If BAS is malfunctioning, the braking distance
in an emer gency braking situation is
increased. #
Dep ress the brake pedal with full forc e in
emer gency braking situations. ABS pre-
ve nts the wheels from locking. The Brake Assist System (BAS) supports
your
emer gency braking situation with additional brake
fo rc e.
If yo u depress the brake pedal quickl y,BAS is
activated:
R BAS automatically boosts the brake pressure.
R BAS can shor tenth e braking distance.
R ABS pr events the wheels from locking.
The brakes will function as usual once youre lease
th e brake pedal. BASis deactivated. F
F
unctions of ESP
unctions of ESP ®
® &
W
W ARNING
ARNING Risk of skidding if ESP ®
is
deactivated
If yo u deactivate ESP ®
, ESP ®
cannot car ryout
ve hicle stabilisation. #
ESP ®
should only be deactivated in the
fo llowing situations. *
N
NOOTE
TE Mercedes-AMG vehicles #
Obser vethe no tes in the Supplement.
Yo u could otherwise failto recognise
dangers. The Electronic
Stability Prog ram (ESP ®
) can moni-
to r and impr ove driving stability and traction in
th efo llowing situations within ph ysical limits:
R When pulling away on wet or slippery car riage-
ways.
R When braking. If
th eve hicle deviates from the direction desired
by the driver, ESP ®
can stabilise theve hicle by
inter vening in thefo llowing ways:
R One or more wheels are braked.
R The engine output is adap ted according tothe
situation.
ESP ®
is deacti vated if theå ESP®
OFF warn-
ing lamp lights up continuously in the instrument
cluster.
Obser vethefo llowing points when ESP ®
is deacti-
va ted:
R Driving stability will no longer be impr oved.
R The drive wheels could spin.
R ETS/4ETS traction control is still active.
% When ESP ®
is deactivated, you are still assis-
te dby ESP ®
when braking.
If th e÷ ESP®
wa rning lamp 0ashes in the
inst rument cluster, one or se veral wheels has
re ached its grip limit:
R Adapt the driving style tosuit the pr evailing
ro ad and weather conditions. 222 222
Driving and parking

Se
Se
tting A
tting A TTENTION ASSI ST
TTENTION ASSIST
Multimedia system:
4 © 5
Settings 5
Assistance
5 Attention Assist
Se
Se tting op
tting op tions
tions #
Select Standard ,Sensitive orOff .
Sugg
Sugg es
esting a rting a r es
est art ar ea
ea #
Select Suggest rest area . #
Activate or deactivate the function.
If AT TENTION ASSIST de tects fatigue or
increasing lack of attention, it suggests a rest
area in the vicinity. #
Select the suggested rest area.
Yo u are guided tothe selected rest area. Cr
Cr
uise contr
uise control and limit ol and limit er
er F
F
unction of cr
unction of cr uise contr
uise controlol
Cruise control regula testh e speed totheva lue
selected bythe driver.
If yo u accelerate toove rtake, forex ample, the
stored speed is not dele ted. If youre mo veyour fo
ot from the accelerator pedal aTer overtaking,
cruise cont rol will resume speed regulation back
to the stored speed.
Yo u can store any speed abo ve20 km/h up tothe
maximum design speed or up tothe set winter
tyre limit.
Obser vethe no tes on driving systems and your
re sponsibility; you may otherwise failto recognise
dangers (/ page 219).
Mer
Mer cedes‑ cedes‑ AMG v
AMG vehicles:
ehicles: cruise cont rol is availa-
ble up toa maximum speed of 250 km/h.
Displ ay
Display s in t
s in the Ins
he Instr trument Display
ument Display
R h (gre y): cruise control is selected but not
yet activated.
R h (gre en): cruise control is active.
A stored speed appears along with theh dis-
pla y.
% The segments extending from the cur rent
stored speed tothe end of the scale, or tothe
set winter tyre limit, light up in the speedome-
te r. Syst Syst
em limits em limits
Cruise control may be unable tomaintain the
stored speed on uphill gradients. The stored
speed is resumed when thegr adient evens out.
Change into a lo werge ar in good time on long and
steep downhill gradients. Take particular no teof
th is when driving a laden vehicle. By doing so, you
will make use of the engine's braking e.ect. This
re lie vesth e load on the brake system and pre-
ve nts the brakes from overheating and wearing
to oqu ickl y.
Do not use cruise control in thefo llowing situa-
tions:
R in tra1c situations which requ ire frequent
ch anges of speed, e.g. in heavy tra1c, on
winding roads
R on slippery roads. Accelerating can cause the
drive wheels tolose traction and theve hicle
could then skid.
R when visibility is poor
F
F unction of t
unction of t he limit
he limiter
er
The limiter restricts the speed of theve hicle. To
re duce the speed tothe set speed, the limiter
applies the brakes automaticall y. Driving and parking
229
229

%
Ifyo u brake, deactivate ESP ®
or if ESP ®
inter-
ve nes, cruise cont rol is deactivated. The varia-
ble limi ter is not deactivated.
Inf
Inf or
ormation on t
mation on t he per
he permanent limit
manent limit er
er
If th eve hicle should ne verex ceed a speci/c
speed (e.g. for driving in winter tyre mode), you
can set this speed with the permanent limiter.
Yo u do this by limiting the speed between
160 km/h and 240 km/h in the multimedia sys-
te m (/ page 232).
Shortly before the set speed is reached, it
appears in the Instrument Displa y.When you con-
/rm the message, display messages no longer
appear until you switch o. theve hicle. The speed
will only be displ ayed again once theve hicle has
been restar ted or if the set speed is changed.
The permanent limi ter does not switch topassive
mode even during kickdown and the driven speed
re mains below the set speed. Se
Se tting t
tting t he limit speed f
he limit speed f or wint
or winter tyr
er tyres
es
Multimedia system:
4 © 5
Settings 5
Vehicle
5 Winter tyres limit #
Select a speed or deactivate the function. A
A
ctiv
ctiv e Dist
e Dist ance Assis
ance Assist DIS t DISTR
TRONIC
ONIC F F
unction of A unction of A ctiv
ctive Dist
e Dist ance Assis
ance Assist DIS t DISTR
TR ONIC
ONIC
Ac tive Distance Assist DISTRONIC maintains the
set speed on free-0owing roads. If vehicles in
front are de tected, the set distance is maintained,
if necessar y,until theve hicle comes toa halt. The
ve hicle accelerates or brakes depending on the
distance totheve hicle in front and the set speed.
The speed and distance totheve hicle in front are
set and sa ved using the steering wheel.
Av ailable speed range:
R V
Vehicles wit
ehicles wit hout Dr
hout Driving Assist
iving Assist ance P
ance Pack
ackag
age:
e:
20 km/h - 200 km/h
R V
Vehicles wit
ehicles wit h Dr
h Driving Assist
iving Assist ance P
ance Pack
ackag
age:
e:
20 km/h - 210 km/h Other
features of Active Distance Assist
DISTRONIC:
R Adjusts the driving style depending on the
selected drive prog ram (fuel-saving, comfor ta-
ble or dynamic)
R Initiates acceleration tothe stored speed if the
turn signal indica tor is switched on tochange
to theove rtaking lane
R V
Vehicles wit
ehicles wit h Dr
h Driving Assist
iving Assist ance P
ance Pack
ackag
age:
e:
- Reacts tostationa ryvehicles de tected in
urban speed ranges (e xcept bicycles and
mo torc yc les)
- Take s one-sided overtaking restrictions
into account on mo torw ays or on multi-
lane roads with separate car riag ewa ys
(countr y-dependent)
V
V ehicles wit
ehicles wit h Dr
h Driving Assist
iving Assist ance P
ance Pack
ackag
age and
e and
P
P ar
ar king P
king P ack
ackag
age:
e: ifth eve hicle has been braked to
a standstill on multi-lane, separate car riag ew ays
by Active Distance Assist DISTRONIC, it can auto-
matical lyfollow theve hicle in front when driving
o. again within 30 seconds. If a critical situation
is de tected when driving o., a visual and acoustic
wa rning is given indicating that the driver must 232 232
Driving and parking

R
Ifth era dar sensors are dirty or co vered.
R In multi-s tore y car par ksor on roads with
steep uphill or downhill gradients.
R Ifth ere are nar row vehicles in front, such as
bicycles or mo torc yc les.
In addition, on slippery roads, braking or acceler-
ating can cause one or se veral wheels tolose
traction and theve hicle could then skid.
Do not use Active Distance Assist DISTRONIC in
th ese situations. &
W
W ARNING
ARNING Risk of accident from accelera-
tion or braking byActive Distance Assist
DISTRONIC
Ac tive Distance Assist DISTRONIC may accel-
erate or brake in thefo llowing cases, for
ex ample:
R Ifth eve hicle pulls away using Active Dis-
ta nce Assist DISTRONIC.
R Ifth e stored speed is called up and is con-
siderably faster or sl owerthan the cur-
re ntly driven speed. R
IfAc tive Distance Assist DISTRONIC no
longer de tects a vehicle in front or does
not react toreleva nt objects. #
Always carefully obser vethe tra1c con-
ditions and be ready tobrake at all
times. #
Take into account the tra1c situation
before calling up the stored speed. &
W
WARNING
ARNING Risk of accident due toinsu1-
cient deceleration byActive Distance
Assist DISTRONIC
Ac tive Distance Assist DISTRONIC brakes your
ve hicle with up to50% of the possible deceler-
ation. If this deceleration is not su1cient,
Ac tive Distance Assist DISTRONIC alerts you
with a visual and acoustic warning. #
Adjust your speed and maintain a suita-
ble distance from theve hicle in front. #
Brake theve hicle yourself and/or take
ev asive action. &
W
WARNING
ARNING Risk of accident if de tection
function of Active Distance Assist
DISTRONIC is impaired
Ac tive Distance Assist DISTRONIC does not
re act or has a limi tedre action:
R when driving on a di.erent lane or when
changing lanes
R topedest rians, animals, bicycles or sta-
tionary vehicles, or unexpected obs tacles
R tocomplex tra1c conditions
R tooncoming vehicles and crossing tra1c
As a result, Active Distance Assist DISTRONIC
may neither give warnings nor inter vene in
such situations. #
Always obser vethe tra1c conditions
carefully and react accordingl y. Oper Oper
ating A
ating A ctiv
ctiv e Dist
e Dist ance Assis
ance Assis t DIS
t DISTR
TRONIC
ONIC
R
R eq
eq uir
uir ements:
ements:
R The electric parking brake is released.
R ESP ®
is activated and is not inter vening. 234
234
Driving and parking

*
N
NO
OTE
TE Damage from automatic braking If one of
thefo llowing functions is switched
on, theve hicle brakes automatically in cer tain
situations:
R Active Brake Assist
R Active Distance Assist DISTRONIC
R HOLD function
R Active Parking Assist
To avoid damage totheve hicle, deactivate
th ese systems in thefo llowing or similar situa-
tions: #
during towing #
in a car wash *
N
NOOTE
TE Damage due tounsuitable car wash #
Before driving into a car wash make sure
th at the car wash is suitable forth eve hi-
cle dimensions. #
Ensu rethere is su1cient ground clear-
ance between the underbody and the
guide rails of the car wash. #
Ensure that the clearance width of the
car wash, in particular the width of the
guide rails, is su1cient. To
avo id damage toyour vehicle when using a car
wa sh, ensu rethefo llowing beforehand:
R Active Distance Assist DISTRONIC is deactiva-
te d.
R The HOLD function is switched o..
R The 360° Camera or there ve rsing camera is
switched o..
R The side windo wsand sliding sunroof are com-
ple tely closed.
R The blo werfo rth eve ntilation/heating is
switched o..
R The windsc reen wiper switch is in position g.
R The key is at a minimum dis tance of 3 m away
from theve hicle. Otherwise theta ilgate could
open unintentionall y. R
In automatic car washes with con veyo r sys-
te ms:
- Neutral iis engaged.
- V
V ehicles wit
ehicles wit h aut
h automatic tr
omatic tr ansmission:
ansmission: If
yo uwo uld like tolea vetheve hicle while it
is being washed, make sure theke y is
located in theve hicle. The park position
j isotherwise automatically engaged.
% If, aTer the car wash, youre mo vethewax
from the windscreen and wiper rubbers, this
will pr event smearing and reduce wiper noise.
A
A ut
ut omatic car w
omatic car w ash mode
ash mode
In car wash mode, theve hicle is prepared for driv-
ing into the automatic car wash. Car wash mode
can be activated at a speed of up to20 km/h
Ac tivate (/ page 339).
The following settings are made when car wash
mode is activated:
R The outside mir rors are folded in.
R Topreve ntthe windscreen washer system
from starting up automaticall y,thera in sensor
is deactivated.
R The rear wind owwiper is deacti vated. 338
338
Maintenance and care